This is a study of the structure of bone mineral on the molecular level; emphasis is placed on the elucidation of the processes involved in bone mineralization. The term structure, here, includes the identification of the chemical phases present in bone and the molecular arrangement of these chemical constituents. Such techniques as X-ray diffraction, infrared spectroscopy, electron microscopy and electron diffraction will be employed in this study. Investigations will be made on normal and pathological bone as well as on synthetic calcium phosphate analogues. In addition, the nature of the mineral phases in pathologically calcified soft tissue will be investigated.